Below you have two graphs - if you click on the forward button, at each click you will see the following appear in sequence: [br][br]1) on the right hand panel you have a function [math]f(x)[/math] (appearing in blue), with its equation; then a point [math]A[/math] on the function; then the tangent line to the function [math]f(x)[/math] at point [math]A[/math], and finally the slope of the tangent line to [math]f(x)[/math] at point [math]A[/math], which is coloured in green. [br][br]2) On the left hand panel you have instead a point [math]B = ( x(A), f \prime (x(A)) )[/math] , then a box where you can input the expression for the derivative of [math]f(x)[/math].